1. Field of the Invention
The present invention relates to a construction machine provided with a reducing agent tank configured to accommodate therein a liquid reducing agent for reducing nitrogen oxide contained in exhaust gas.
2. Description of the Background Art
FIG. 5 is a partially enlarged perspective view of a construction machine described in Japanese Unexamined Patent Publication No. 2011-64132 (hereinafter, called as Patent Literature 1).
The construction machine described in Patent Literature 1 is provided with an upper frame 20 provided on a lower traveling body, a reducing agent tank 21 provided on the upper frame 20, a tank cover 22 for covering the reducing agent tank 21, and a front cover 23 disposed at a front position of the tank cover 22.
The reducing agent tank 21 accommodates therein a liquid reducing agent such as urea water for reducing nitrogen oxide contained in exhaust gas.
The tank cover 22 is provided with a covering portion 22a which covers the reducing agent tank 21 from above, and which includes an opening/closing lid 24 for allowing the operator to replenish the reducing agent tank 21 with a liquid reducing agent; and a passage portion 22b disposed laterally offset from the upper surface of the reducing agent tank 21.
The front cover 23 includes stairs 25 for allowing the operator to climb on the passage portion 22b of the tank cover 22.
When the operator climbs on the passage portion 22b of the tank cover 22 using the stairs 25, the operator walks on the passage portion 22b toward a device provided on the upper frame 20 (e.g. an engine provided in an engine room 26) for maintenance of the device.
In other words, in the construction machine described in Patent Literature 1, the upper surface of the tank cover (the upper surface of the passage portion 22b) is used as a passage surface on which the operator walks toward the device for maintenance service.
In the construction machine described in Patent Literature 1, the operator is also allowed to replenish the reducing agent tank 21 with a liquid reducing agent via the opening/closing lid 24 in a state that the operator stands on the passage surface (the upper surface of the passage portion 22b).
In the construction machine described in Patent Literature 1, however, the reducing agent tank 21 is provided below the passage surface. Therefore, the operator is forced to bend forward in a narrow space in order to replenish a liquid reducing agent and feels stressful. This is burden to the operator.